Flashing light signal



Oct. 4, 1938. 5 BRYANT 2,132,097

FLASHING'LIGHT SIGNAL Filed Sept, 8, 1934 LO v Patented Oct. 4, 1938UNITED STATES PN FFICE FLASHING LIGHT SIGNAL ter. N. Y.

Application September 8, 1934, Serial No. 743,232

2 (Jlaims.

This invention relatesto flashing light signals, and more particularlyto means for cutting in a reserve lamp .for signals of this type uponfailure of the lamp normally in use.

In certain types of signals giving intermittent or flashing indications,such as are used for example for lighthouse beacons, highway crossingsignals on railroads, and the like, it is sometimes desirable to providea reserve lamp and to lo cut in this lamp automatically when the lightnormally in use burns out.

In accordance with thisinvention, it is proposed to employ a light-outrelay which is energized in series with the filament in the lamp isnormally in use, and which when de-energized cuts in a reserve lamp, andto employ means for maintaining said relay energized at the time thelamp is to be extinguished to give the flashing indication.

The accompanying drawing illustrates in a diagrammatic and conventionalmanner one specific embodiment of the invention.

The invention contemplates a suitable light projecting unit, comprisinglenses, reflectors and the like, to provide the desired light beam whenthe lamp of the signal is lighted. This light projecting unit may takevarious forms, and is indicated conventionally as a lens I. It is alsocontemplated that this light projecting unit will be provided with twoincandescent lamps of the usual concentrated filament type, one of theselamps NL normally in use being preferably disposed at the focal point ofthe light projecting unit, and the other reserve lamp RL as near to suchfocal point as space will permit. The reserve lamp RL may have a greatercandle power to compensate for being out of focus, or both lamps may bedisposed symmetrically with respect to the focal point.

0 The lighting of the signal is assumed to be controlled by a suitabeflasher relay FL or equivalent means. One type of such flasher relay.such as disclosed for example, in the Patent 1,969,065, granted 8/7/34to O. S. Field, is illustrated di- 45 agrammatically and comprises anarmature 2 pivoted on a middle core 4 and adapted to be rocked or tiltedin opposite directions by the energization of coils 6 and l on theoutside cores 3 and 5. The armature 2 carries an insulated 5o finger 8which'engages contacts to short-circuit each coil 6 and 1 in turn as thearmature is rocked by that coil. Two fingers 9 and i0 carril by thearmature engage contacts when the armature is tilted in one direction toclose the on circuit for lighting the lamps.

the lighting circuit,

A light-out relay L0 is connected in series with the filament of thenormal lamp NL, and has an armature finger ii closing a back contact toinclude the reserve lamp RL in the lighting circuit. 5

A resistance R is connected across the contacts 9 and ill of the flasherrelay FL; and the operating characteristics of the relay L0 and thevalue of this resistance R are so selected or adjusted that, when thisresistance is included in 1 sufl'icient current flows through the relayL0 to maintain its armature attracted, but this current is insuflicientto heat the filament to give off any substantial amount of light. 15

The parts are illustrated in the inactive condition. When the switch 82is closed, current may flow from the battery B or other suitable source,through the resistance R, relay L0 and filament of the normal lamp NL.Current also so flows through the coils 6 and l of the flasher relay FLin series over a circuit readily traced on the drawing. The magneticcircuits for these coils will not be exactly balanced and the pull ofone will predominate, rocking the armature 28 2 in one direction. Uponsuch movement of the armature, the coil 6 or I causing such movement, asthe case may be, is short-circuited by the contact finger 8, therebypermitting the other coil to rock the armature in the opposite direc- 80I tion. The coils 6 and 1 are thus alternately energized to rock thearmature back and forth to intermittently close the contacts 9-40.

Each time the contacts 9-H) of flasher relay FL close the resistance Ris shunted or short- 85 circuited and suflicient current flows throughthe normal lamp NL to light it and' display the de-v sired indication.When these contacts 9-H! open, sumcient current flows through theresistance R to maintain the armature of relay L0 40 attracted, althoughthe lamp NL is not efiectively lighted and failing to give enough lightfor an indication, it can be considered to be effectively extinguished.

So long as the filament of the normal lamp NL is intact, it isintermittently lighted by the closing of the contacts 9-40 of theflasher relay FL, and the light-out relay L0 is maintained energizedsumciently to hold open its back contact I I; but if this filamentshould burn out, the relay L0 is de-energized, and includes the reservelamp RL in the lighting circuit through the back contact H of said relayL0.

The resistance R not only serves to provide current for maintaining therelay energized while ll the lamp NL is effectively extinguished, butalso minimizes the arcing and sparking at the contacts 8-" 01' theflasher relay FL.

The structural organization shown and described is merely illustrative.Any suitable type oi flashing means may be employed, operated by directcurrent or alternating current; and various modifications, adaptations,and additions may be made to the speciflc embodiment of the inventiondisclosed, without departing from the invention.

What I claim is:

1. A flashing light signal comprising, normal operation and reservelamps; a light-out relay; a circuit including in series a source ofcurrent, a resistance, the relay winding and the fllament oi the normallamp, the resistance of said circuit being too great to eirectivelyenergize the lamp; means operating contacts for intermittentlyshort-circuiting said resistance to cause the lamp to be eflectivelyenergized, the winding of said relay being maintained energized toattract its armature so long as the fllament of the normal lamp isintact; and a circuit controlled by said relay for connecting thereserve lamp in multiple with said relay and normal lamp when the relaywinding is deenergized.

2. In a flashing light signal, in combination, a normal operation lamp,a reserve lamp. a single wound light-out relay, a separate resistance, asource 01' electrical energy, a control switch,a circuit including inseries, the control switch, the source, the normal lamp, the entirewinding of the relay, and the resistance, thecircuit being of such aresistance that the relay armature is held up but the normal lamp is noteffectively energized, electro-magnetically operated contact meansenergized through said control switch (or automatically andintermittently making and breaking a shunt around the separateresistance whereby the normal lamp is eflectively energized when theresistance is shunted out 01' the circuit, the resistance beingconnected directly across'the said contact means to minimize arcing atsaid contact means, the reserve lamp being connected in multiple withthe normal lamp and the relay winding through a back contact of therelay, whereby to replace the normal lamp upon failure of the normallamp, and whereby, following a failure of the normal lamp, the manualreplacement of the normal lamp by a new lamp, automatically restores thesystem to normal operation.

STANLEY C. BRYANT.

